1. Field of Invention
The present invention relates to combustion fuels. In particular, it relates to a bio-synthetic fact composition and method of making and using the same.
2. Description of Related Art
According to the article, “Duckweed Aquaculture, A New Aquatic Fanning System for Developing Countries” by Paul Skillicorn, William Spira, and William Journey, The World Bank Emena Technical Department Agriculture Division: “www.p2pays.org/ref/09/08875.htm:                “Duckweed species are small floating aquatic plants found worldwide and often seen growing in thick, blanket-like mats on still, nutrient-rich fresh and brackish waters. They are monocotyledons belonging to the botanical family Lemnaceae and are classified as higher plants, or macrophytes, although they are often mistaken for algae. The family consists of four genera, Lemna, Spirodela, Wolffia, and Wolffiella, among which about 40 species have been identified so far.        All species occasionally produce tiny, almost invisible flowers and seeds, but what triggers flowering is unknown. Many species of duckweed cope with low temperatures by forming a special starchy “survival” frond known as a turion. With cold weather, the turion forms and sinks to the bottom of the pond where it remains dormant until rising temperatures in the spring trigger resumption of normal growth.        Morphology Duckweed species are the smallest of all flowering plants. Their structural and functional features have been simplified by natural selection to only those necessary to survive in an aquatic environment. An individual duckweed frond has no leaf, stem, or specialized structures; the entire plant consists of a flat, ovoid frond . . . . Many species may have hair-like rootlets which function as stability organs.        Species of the genus Spirodela have the largest fronds, measuring as much as 20 mm across, while those of Wolffia species are 2 mm or less in diameter. Lemna species are intermediate size at 6-8 mm. Compared with most plants, duckweed fronds have little fiber—as little as 5 percent in cultured plants—because they do not need structural tissue to support leaves or sterns. As a result virtually all tissue is metabolically active and useful as a feed or food product. This important characteristic contrasts favorably with many terrestrial crops such as soybeans, rice, or maize, most of whose total biomass is left behind after the useful parts have been harvested.        Distribution Duckweed species are adapted to a wide variety of geographic and climatic zones and can be found in all but waterless deserts and permanently frozen polar regions. Most, however, are found in moderate climates of tropical and temperate zones. Many species can survive temperature extremes, but grow fastest under warm, sunny conditions. They are spread by floods and aquatic birds.        Duckweed species have an inherent capability to exploit favorable ecological conditions by growing extremely rapidly. Their wide geographic distribution indicates a high probability of ample genetic diversity and good potential to improve their agronomic characteristics through selective breeding. Native species are almost always available and can be collected and cultivated where water is available, including moderately saline environments.        Growth conditions The natural habitat of duckweed is floating freely on the surface of fresh or brackish water sheltered from wind and wave action by surrounding vegetation. The most favorable circumstance is water with decaying organic material to provide duckweed with a steady supply of growth nutrients and trace elements. A dense cover of duckweed shuts out light and inhibits competing submerged aquatic plants, including algae.        Duckweed fronds are not anchored in soil, but float freely on the surface of a body of water. They can be dispersed by fast currents or pushed toward a bank by wind and wave action. If the plants become piled up in deep layers the lowest layer will be cut off from light and will eventually die. Plants pushed from the water onto a bank will also dry out and die. Disruption of the complete cover on the water's surface permits the growth of algae and other submerged plants that can become dominant and inhibit further growth of a duckweed colony.        To cultivate duckweed a farmer needs to organize and maintain conditions that mimic the natural environmental niche of duckweed: a sheltered, pond-like culture plot and a constant supply of water and nutrients from organic or mineral fertilizers. Wastewater effluent rich in organic material is a particularly valuable asset for cultivating duckweed because it provides a steady supply of essential nutrients and water.        In this case there is a coincidence of interests between a municipal government, which would treat the wastewater if it could afford to do so, and nearby farmers, who can profitably do so.        Production rates Duckweed reproduction is primarily vegetative. Daughter fronds bud from reproductive pockets on the side of a mature frond. An individual frond may produce as many as 10 generations of progeny over a period of 10 days to several weeks before dying. As the frond ages, its fiber and mineral content increases, and it reproduces at a slower rate.        Duckweed plants can double their mass in less than two days under ideal conditions of nutrient availability, sunlight, and temperature. This is faster than almost any other higher plant. Under experimental conditions their production rate can approach an extrapolated yield or four metric tons/ha/day of fresh plant biomass, or about 80 metric tons/ha/year of solid material. This pattern more closely resembles the exponential growth of unicellular algae than that of higher plants and denotes an unusually high biological potential.        Average growth rates of unmanaged colonies of duckweed will be reduced by a variety of stresses: nutrient scarcity or imbalance; toxins; extremes of pH and temperature; crowding by overgrowth of the colony; and competition from other plants for light and nutrients.        
Actual yields of fresh material from commercial-scale cultivation of Spirodela, Lemna, and Wolffia species at the Mirzapur experimental site in Bangladesh range from 0.5 to 1.5 metric tons/ha/day, which is equivalent to 13 to 38 metric tons/ha/year of solid material.                Nutritional value Fresh duckweed fronds contain 92 to 94 percent water. Fiber and ash content is higher and protein content lower in duckweed colonies with slow growth. The solid fraction of a wild colony of duckweed growing on nutrient-poor water typically ranges from 15 to 25 percent protein and from 15 to 30 percent fiber. Duckweed grown under ideal conditions and harvested regularly will have a fiber content of 5 to 15 percent and a protein content of 35 to 45 percent, depending on the species involved, . . . . Data were obtained from duckweed colonies growing on a wastewater treatment lagoon and from a duckweed culture enriched with fertilizer.        Duckweed protein has higher concentrations of the essential amino acids, lysine and methionine, than most plant proteins and more closely resembles animal protein in that respect, . . . compares the lysine and methionine concentrations of proteins from several sources with the FAO standard recommended for human nutrition.        . . .        Cultured duckweed also has high concentrations of trace minerals and pigments, particularly beta carotene and xanthophyll that make duckweed meal an especially valuable supplement for poultry and other animal feeds. The total content of carotenoids in duckweed meal is 10 times higher than that in terrestrial plants; xanthophylls concentrations of over 1,000 parts per million (ppm) were documented in poultry feeding trials in Peru . . . . This is economically important because of the relatively high cost of the pigment supplement in poultry feed.        . . .        A monoculture of Nile tilapia and a polyculture of Chinese and Indian carp species were observed to feed readily on fresh duckweed in the Mirzapur experimental program. Utilizing duckweed in its fresh, green state as a fish feed minimizes handling and processing costs. The nutritional requirements of fish appear to be met completely in ponds receiving only fresh duckweed, despite the relatively dilute concentration of nutrients in the fresh plants. The protein content of duckweed is compared with several animal feed ingredients . . . .”        
Although duckweed is as prolific as algae, it is only now being considered as a feedstock for biofuel. See for example, “Duckweed: A biofuel and waste treatment”, Science News published Apr. 9, 2009; www.upi.com/Science_News/2009/04/09/Duckweed-A-biofuel- . . . , wherein North Carolina State University researchers propose to covert the starch from duckweed into ethanol using the same distillation facilities currently used for corn. Although this is a better feedstock, the high energy cost to make ethanol and distill it for separation makes this approach unattractive. For a similar ethanol production proposal, also see “Growing Duckweed to Recover Nutrients from Wastewaters and for Production of Fuel Ethanol and Animal Feed”; Wiley InterScience: JOURNALS-CLEAN-Soil, Air, Water; www3.intersicince.wiley.com/journal/121645918/abstract?Cr. This approach uses amylases for enzymatic hydrolysis of the duckweed biomass with a reducing sugar to produce ethanol for subsequent extraction.
The present method produces a bio-synthetic fuel without the need for oil or alcohol extraction and is suitable for co-firing with liquid as well as solid carbon based fuels.